Influence Of Driving Equipment Vibration On Bogie Frame Fatigue Strength

As the main load-bearing structure of bogie and complication of loading state, the strength and reliability of frame have a significant impact on the locomotive dynamic performance and safety. When assessment of fatigue strength of frame in engineering applications, the dynamic load of driving equipment often adopt value of its self-acceleration with relevant standards, this value, which is as an input reference value of loads. But in practical applications, due to vibration characteristics of driving equipment is not considered, using this acceleration as a static load input can achieve a conservative analysis result. At the internal and abroad, the analyses of dynamic load which act on frame from vibration of driving equipment have a little research. In order to reveal the influence discipline of this vibration which effect on fatigue strength of frame, and therefore, the range, as a reference value of the frame structure and fatigue strength experiment loads, still study in future.This thesis established a simplified model consisting of three rigid bodies for the bogie firstly. Based on the basic theory and analyzed the vibration with the flexible suspension driving equipment and different speed grades, this analysis method qualitatively investigate the vertical equivalent dynamic loads which effect on fatigue strength of frame by driving equipment. Even more, the method of equivalent dynamic load coefficient is investigated from two field to verify its feasibility and correctness, and the value range of equivalent dynamic load coefficient adopt its statistics value to express. Finally, the result of initial value range is from zero to four.Adopting the commercial software SIMPACK and considering the nonlinear relationship between wheel and rail, established a simplified rigid calculation model of single whole bogie which conclude two difference structure, axle suspension and flexible suspension which define by the suspension style of driving equipment on frame, is to analyze the value range of vertical equivalent dynamic load coefficient through this simple model. What’s more, to analyze the influence through the comparison with the difference centroid location of driving equipment, among it, the condition of centroid location is offset to axle of wheelset and suspension point of driving equipment in middle beam along the longitudinal direction. At next step, established model of the whole locomotive and analyzed it in the same method. The result of research shows that the range of vertical equipment dynamic load coefficient is 0-0.891 and 0-0.376, among it, the former is from the structure of axle suspension, and the later is flexible suspension.In the end, based on the statistical theory, the value range of vertical equivalent dynamic load coefficient holds on a detail data, and the last of its value range is 0.291～0.891, which structure is axle suspension; the other one is 0.125～0.376, which structure is flexible suspension. The result of this research in this thesis can provide a certain reference value when assessment of fatigue strength of frame, experiment loads and structure design in lightweight, it has strong practical significance project.